I am looking forward to participating in a TEDMED Google+ Hangout, March 25th at noon, on the topic of Health Myths. You should come participate! To quote a blogpost from the TEDMED folks:You can get the flu – or worse — from a vaccine. Only old folks get strokes and heart attacks. Calories in, calories out. X-rays cause cancer. Sleep eight hours a night and drink eight glasses of water a day. Skip the sunscreen on a cloudy day. Take a multivitamin every day, just to be on the safe side. An apple a day keeps the doctor away. Exercise more to lose weight.What are the most popular health myths, and how do they spread? Does social media spread scams faster that it helps dispel them? How can doctors help patients practice proven steps for prevention – and still keep up on current research themselves?Great questions all. Leaving aside a quibble about X-rays and cancer (about which the jury seems to be out still, or at least conflicted), the list above points to something important about so-called health myths: they come in many different flavors. Flu is not caused by a vaccine; that's just wrong. But older people are generally speaking indeed at higher risk of strokes and heart attacks (though of course it's not only them). "Exercise more to lose weight" isn't exactly true, but exercising is one way to keep off weight lost through reduced caloric intake (and - can lead to weight loss by itself, actually).All this is just to say that one myth may be quite unlike another. They are as diverse in their way as any kind of belief. Thinking more about it, I would like to jettison the whole term "myth" altogether. We all have beliefs. Some of them hew fairly closely to the science - others don't.What the summary above artfully avoids is potentially the most interesting question: who believes most in scientifically unfounded assertions? Is it patients, or doctors (and nurses) themselves? I would wager that we are all in the same boat. Much as doctors don't know statistics, much of us don't practice according to the medical evidence either.If you push a little bit on many medical assertions once held to be widely agreed-upon truths, you will find yourself coming away with a handful of dust -- and more, if you push harder. Does everyone need screening for prostate cancer? No. What about breast cancer? Unclear. Does vitamin D help much, say, for heart disease (except in older populations at risk of fracture)? Maybe, though the evidence is thin. If we treat mild hypertension, can we expect mortality benefits? Doesn't seem that way. Yet practices based on these suppositions persist.In other words, doctors are as much myth-makers, and myth-peddlers, as patients. Which means we all need to reevaluate our relationship to science. If doctors can be as uncertain as patients, shouldn't we be skeptical of the hierarchy that still obtains in certain quarters? Shouldn't we come together to discuss our fears, preconceptions, worries, and expectations?